i have a grasshopper 721D g2 and it is probably 3 or 4 years old and i talked to the grasshopper rep the other day and he said the new ones have different decks than the old ones. He said that the new one let more air in to shoot the grass out faster meaning being able to mow faster. has any one used the older style deck and is currently using the new style deck? can you tell any differnce in the way the new deck cut? and will the new mowers mow faster because of the new decks?